Novel organophosphorus compounds



United States Patent "ice 3,261,857 NOVEL ORGANOPHOSPHORUS COMPGUNDSMichael McKay Rauhut, N orwalk, C0nn., assignor to American CyanamidCompany, Stamford, Conn., a corporation of Maine N0 Drawing. Filed Apr.8, 1965, Ser, No. 446,739 6 Claims. (Cl. 260-4293) invention:

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These salts may, in turn, be converted to their corresponding acids,esters, and other salts, as will be seen hereinafter.

Generically, the products of the present invention may be Written asfollows:

i XSY wherein X is selected from Re H -2.l1 HCCH Ho-OH Rd l l R o o R aCH 113 \R4 wherein Y represents hydrogen; ammonium; lithium, potassium,and sodium; an alkaline earth metal including calcium, strontium, andbarium, and the like; a heavy metal, such as copper, mercury, nickel,zinc and the like; other metals, such as aluminum, magnesium, and thelike; a substituted and unsubstituted, saturated and unsaturated,branched and straight chain alkyl radical having from 1 "to 18 carbonatoms; a substituted and unsubstituted, satreaction temperatures in therange of 50 C. to C 3,261,857 Patented July 19, 1966 urated andunsaturated alicyclic radical; a substituted and unsubstituted arylradical. Re and Rd, respectively, of the above represent substituted andunsubstituted, saturated and unsaturated, branched and straight chainalkyl having from 1 to 18 carbon atoms, and, preferably, saidsubstituted alkyl radicals have their substituents on a carbon atom atleast 3 carbon atoms removed from the phosphorus atom; saturated andunsaturated, substituted and unsubstituted alicyclic radicals;substituted and unsubstituted aryl radicals; and Re and Rd,respectively, are attached directly to the phosphorus atom through acarbon atom. Re and Rd may be the same or difi'erent radicals.

R to R in the above formula each represent alkyl of 1 to 10 carbon atomsand, as will be seenhereinafter, R R R R R and R may be the same ordilferent radicals.

Generally, the salt of the dithiophosphinic acid corresponding to thesecondary phosphine reactant is first formed and is then converted toits corresponding acid or ester. Typically,2,4,6-triisopropyl-1,3,-dioxa-5-phosphacyclohexane is reacted withaqueous ammonium hydroxide and sulfur to produce the ammonium salt of2,4,6 triisopropyl-1,3-dioXa-5-phosphacyclohexane-S-dithioic acid,which, in turn, is dissolved in water and acidified with HCl to yield2,4,6-triisopropyl-1,3-dioxa-5-phosphacyclohexane-S-dithioic acid.

The metal salt of this acid may be prepared by reacting the acid with analkali metal hydroxide, for example, such as NaOH. In turn, this metalsalt, such as the sodium salt, is reacted with a halogen-substitutedalkyl or alicyclic compound to produce the corresponding ester, as willbe seen hereinafter. -These esters are produced at or at temperatures upto about the reflux temperature of any solvent employed.

Typical halogen substituted compounds suitable for preparing theseesters are l-chloropropane, 3-chlorohexane l-bromobutene-Z,1-chloro-3-ethoxy-heptane, l-bromo cyclohexane-Z, and the like.

Another route to the esters involves reacting the free acids of thepresent invention with alcohols or olefins to produce correspondingesters.

Typical secondary phosphines corresponding to the formulae and usefulfor preparing the products of the present invention are:

Diphenylphosphine; Bis(4-chlorophenyl)phosphine; Dibutylphosphine;

Didodecylphosphine; Bis(2-phenylethyl)phosphine; Dicyclohexylphosphine;

Bis 3-ethylhexyl) phosphine;

Bis( 2,4,4-trimethylpentyl) phosphine;

Bis 3-chloropropyl phosphine; Bis(2-butenyl)phosphine;

Ethylhexylphosphine;

Dioctylphosphine;

Diisooctylphosphine;

Bis 3 -methoxycyclohexyl )phosphine Bis(3-ethoxycyclopentenyl)phosphine; 2,4,6-His 3-heptyl) l,3-dioxa-5-phosphacyclol1exane;

3 2- 3 -hexyl)-4,6-diisopropy1-1,3-dioxa-S-phosphacyclohexane; Bis(2-phenoxyethyl) phosphine; Bis(2-aminoethy1) phosphine; Bis2-nitropropyl) phosphine; Bis (2-sulfoethyl )phosphine; Bis(carbamylmethyl phosphine; Bis 2-ureidoethyl phosphine; Bis(hydroxymethyl) phosphine, Bis( l-hydroxyhexyl phosphine; Bis3-carboxypropyl phosphine; Bis 3-carbethoxypropyl)phosphine; Bis(4-aminophenyl) phosphine; Bis [2 (4-aminophenyl ethyl] phosphine;

and the like; and mixtures thereof, such as a reactant mixture ofdioctylphosphine and diisooctylphosphine, and similar mixtures.

The 2,4,6 trisecondaryalkyl-l,3-dioxa-5-phosphacyclohexanes contemplatedherein are prepared as described in copending U.S. application SerialNo. 766,656, filed October 13, 1958, now U.S. Patent 2,984,683, which isincorporated herein by reference. The 2,4,6-triisopropyl-1,3-dioxa-5-phosphacyclohexane referred to above, for example,. isprepared as shown in Examples A through C, below.

Among the basic organic and inorganic reagents suitable for the presentinvention are alkali hydroxides, including sodium, potassium andlithium; alkali carbonates, such as sodium carbonate; alkaline earthhydroxides, such as the hydroxides of barium, magnesium, strontium, andcalcium; weak bases, such as ammonium hydroxide, basic organic amine,such as pyridine, cyclohexylamine, aniline, primary alkyl (C -C amine,secondary alkyl (C -C amine, tertiary alkyl (C -C amine, piperidine,2-hydroxyethylamine, bis(2-hydroxyethyl)amine and tris (Z-hydroxyethyl)amine.

If desired the reaction of a secondary phosphine, ac-

cording to the instant discovery, with sulfur, water, and

a basic reagent may be carried out in the presence of a water-soluble,inert, organic solvent in which the basic reagent is soluble. Includedamong these solvents are lower aliphatic alcohols; cyclic ethers, suchas tetrahydrofuran and dioxane; methyl ethyl ketone; and the like.

The reaction of the present invention wherein a secondary phosphine isbrought into intimate contact with sulfur, water, and' a base reagent isbest carried out, according to the instant discovery, at temperatures inthe range of 0 C. to 100 C., preferably 15 C. to 75 C. As will be seenhereinafter, the ammonium salt thus prepared may be reacted with anacid, such as HCl, dilute sulfuric acid, or methane sulfonic acid toproduce the secondary dithiophosphinic acid. These reactions generallyare made to take place at temperatures in the range of --30 C. to 75 C.,preferably C. to 50 C.

While atmospheric pressures are desirable for this type of reaction,superand sub-atmospheric pressures are suitable.

The reactants in the various reactions contemplated herein are generallypresent in stoichiometric quantities, although substantially greater orsubstantially less than stoichiometric amounts are suitable withoutupsetting the nature of the reaction.

The products of the present invention are useful as oil additives andherbicides. It is found that the watersoluble compounds are eflectiveherbicides, whereas the water insoluble salts of the phosphacyclohexanederivatives of the present invention are effective additives whichenhance the lubricity of oil.

Included among the substitutents contemplated for R0 and Rd,respectively, in the formula given above are alkoxy, halogen, aryloxy,aralkoxy, alkaryloxy, amino, nitro, ureido, sulfo, hydroxyl, carbamyl,acyloxy, carbalkoxy, carboxy, aryl, and the like.

The following examples illustrate methods of preparing A. typical2,4,6-trisecondaryalkyl-1,3-dioxa-5-phosphacyclohexane secondaryphosphines of the type contemplated herein:

EXAMPLE A 2,4 ,6 -triis0pr0 pyl-I ,3-dioxa-S-phosphacycloh exane Aone-liter, three-necked reactor flask is equipped with a gas inlet tube,an addition funnel, a mechanical stirrer and a gas bubbler device sodisposed that all exit gases from the flask pass upwardly therethrough,the bubbler device comprising a column containing a two-inch head ofwater. The reactor flask is charged with a solution mixture at ambienttemperature (21 C.-23 C.) of 200 milliliters of a concentrated aqueoussolution of hydrochloric acid containing 37.7 percent HCl by weight and200 milliliters of tetrahydrofuran.

Subsequently, the flask system and the charge are purged substantiallyfree of oxygen-containing gas with nitrogen gas, and then a total of 108grams (1.5 moles) of isobutyraldehyde and 17 grams (0.5 mole) of gaseousphosphine, at ambient temperature (21 C.23 C.), is slowly andcontinuously introduced into the charge over a period of 30 minutes.

A reaction mixture results which, after settling for 30 minutes, leavesan upper organic layer or phase which is separated from the remainingreaction mixture and distilled under reduced pressure. A total of 91grams (78 percent of theory) of product 2,4,6-triisopropyl-l,3-dioxa-S-phosphacyc1ohexane is thus collected as a colorless liquidhaving a boiling point of C.-101 C. at 8 millimeters pressure. Thematerial has a pungent odor and a refractive index of n =1.4602

Analysis.Calculated for C H O P: C, 62.04; H, 10.85; P, 13.34. Found: C,61.82; H, 10.78; P, 13.26.

EXAMPLE B 2,4,6-tris(3-h eptyl) -1,3-dioxa-5-phosphacyclohexane Thereactor flask in Example A is charged instead with a mixture ofmilliliters of a concentrated aqueous solution of hydrochloric acidcontaining 37.7 percent HCl by weight and 125 milliliters oftetrahydrofuran, and a total of 66.5 grams (0.52 mole) ofZ-ethylhexandehyde and 6.2 grams (0.18 mole) of phosphine at ambienttemperature (21 C.-23 C.) is added uniformly with agitation in thecourse of 30 minutes. A reaction mixture results having an upper organicphase which is separated from the remaining reaction mixture anddistilled under reduced pressure. A total of 61.1 grams (90 percent oftheory) of 2,4,6-tris(3-heptyl)-1,3-dioxa-5-phosphacyclohexane as acolorless liquid product is recovered having a boiling point of 148 C.to 153 C. at 0.025 millimeter pressure and having a refractive index ofn =1.4709.

Analysis.-Calculated for C H O P: C, 71.95; H, 12.33; P, 7.73. Found: C,71.87; H, 12.62; P, 7.57.

EXAMPLE C 2,4,6-triis0pr0pyl-1,3-di0xa-5-ph0spl1acyclohexane-S-dithioz'c acid A mixture of 235 grams (1.0 mole) of 2,4,6-triisopropyl- 1,3 dioxa-S-phosphacyclohexane, 64 grams (2.0 moles) of sulfur, 350milliliters of concentrated ammonium hydroxide solution, and 350milliliters of water is heated at 85 C. in an atmosphere of nitrogen for1 hour. The resulting colorless solution is filtered while still warm toremove a small excess of sulfur and then cooled to 0 C. in an ice bath.The product recovered is 265 grams (85 percent by weight of theory) ofthe ammonium salt of2,4,6-triisopropyl-l,3-dioxa-5-phosphacycloheXane-5-dithioic acid whichcrystallizes on standing. Two recrystallizations of this product from abenzeneacetone mixture give an analytical sample melting at about 185 C.with decomposition. The melting point depends on the rate of heating.

Analysis.-Calculated for: C H NO PS C, 45.98; H, 9.00; P, 9.88. Found:C, 46.21; H, 8.99; P, 9.78, 9.99.

A portion of this ammonium salt product is dissolved in water, and theresulting solution acidified with hydrochloric acid. An oil separatesout and crystallizes on standing to yield the corresponding2,4,6-triisopropyl-1,3- dioxa-5-phosphacyclohexane-5-dithioic acidhaving a melting point of 48 C.51 C.

Analysis.Calculated for C H O PS C, 48.62; P, 10.45; S, 21.63. Found: C,48.85; P, 10.56; S, 21.48.

EXAMPLE II Sodium salt of 2,4,6-triispropyl-1,3-dioxa-5-phosphacyclohexane-S-dithioic acid A stirred mixture of 23.5 grams (0.1mole) of 2,4,6- triisopropyl-1,3-dioxa-S-phosphacyclohexane, 6.4 grams(0.2 mole) of sulfur, 4.0 grams (0.1 mole) of sodium hydroxide, and 70milliliters of water'is heated at 75 C. in an atmosphere of nitrogen for1 hour. The resulting clear solution is evaporated to dryness and acrystalline residue is formed which is extracted with acetone. Theacetone extract is evaporated to dryness and the residue obtainedrecrystallized from a benzene-acetone mixture to obtain the sodium saltof 2,4,6-triisopropyl-1,3-dioxa-5-phosphacyclohexane-S-dithioic acidhaving a melting point of 283 C.285 C.

EXAMPLE III Sodium salt of diphenyldithiophosphinic acid Example I,above, is repeated with the exception that 1 mole of diphenylphosphineis used as the secondary phosphine reactant. The correspondingdipheny-ldithiophosphinic acid is obtained andhas a melting point of 52C.55 C. By exactly neutralizing this free acid with a dilute sodiumhydroxide solution, the corresponding sodium salt thereof is produced.

EXAMPLE IV Sodium salt of bis(4-clzlorophenyl)dithiophosphinic acidExample 1, above, is repeated with the exception that 1 mole ofbis(4-chlorophenyl)phosphine is used as the secondary phosphine. Thecorresponding bis(4-chlorophenyl)dithiophosphinic acid is obtained. Byexactly neutralizing this free acid with a dilute sodium hydroxide solu-'tion, the corresponding sodium salt thereof is produced.

EXAMPLE V Ammonium salt of dibutylditlziophosphinic acidDibutylphosphine 14.6 grams, 0.1 mole) is added drop- Wise with stirringto a mixture of 7.0 grams (0.22 mole) of sulfur, 50 milliliters ofammonium hydroxide, and 50 milliliters of water in an atmosphere ofnitrogen. During the addition, which takes minutes, an exothermicreaction occurs and the temperature is maintained at 25 C.27 C. byintermittent cooling. This reaction mixture is stirred at about roomtemperature (21 C.23 C.) for 1.5 hours. The excess sulfur present at theend of this period is filtered off and the filtrate evaporated todryness, thus recovering the ammonium salt of dibutyldithiophosphinicacid having a melting point of 82 C.88 C. Two recrystallizations of thissalt from benzene provide 16.8 grams of analytically pure product havinga melting point of 97 C.99 C.

EXAMPLE VI the solution obtained after removing excess sulfur is phinicacid having a melting point of 89 C.90" C.

EXAMPLE VII Nickel salt of didodecylditlziophosphinic acid Two grams(0.005 mole) of didodecylphosphine, 0.39 gram (0.012 mole) of sulfur, 10milliliters of water, 10 milliliters of ammonium hydroxide, and 20milliliters of methanol are combined and stirred at 60 C. in anatmosphere of nitrogen for 20 minutes. At the end of this period theexcess sulfur remaining is filtered off and the filtrate thus obtainedis concentrated under reduced pressure to obtain ammoniumdidodecyldithiosphinate. This ammonium salt is combined with 20milliliters of water and 3 milliliters of methanol and added to asolution of 1 gram of nickel (II) chloride hexahydrate in 10milliliters-of water. A blue solid separates out which is extracted withthree 35- milliliter portions of ether. The resulting dark blue ethersolution is concentrated under reduced pressure and cooled to obtain 1.7grams of blue crystals melting at 72 C.74 C. Recrystallization from abenzene-methanol solution provides 1.6 grams of the nickel salt ofdidodecyldithiophosphinic acid having a melting point of 72 C.73 C.

EXAMPLE VIII Ammonium salt of bis(2-phenylethyl) dithiophosphinic acidBis(2-phenylethyl)phosphine (9.5 grams, 0.04 mole) is added dropwise toa stirred mixture of 2.75 grams (0.086 mole) of sulfur, 20 millilitersof ammonium hydroxide, and 20 milliliters of water in an atmosphere ofnitrogen. During the addition, which takes ten minutes, an exothermicreaction occurs and the temperature is maintained at 25 C.30 C. byintermittent cooling. The reaction mixture is then stirred at about roomtemperature (21 C.-

23 C.) for 3 hours. The excess sulfur present at the end of this periodis filtered off and the filtrate evaporated to dryness, thus recoveringthe ammonium salt of bis(2-phenylethyl)dithiophosphinic acid having amelting point of C.203 C. Two recrystallizations from a benzene-methanolsolution raise the melting point to 201 C.203 C.

EXAMPLE IX Nickel salt of bis(2-phenylethyl)dithiophosphinic acidAmmonium salt of dicyclohexyldithioplzosphinic acid A stirred mixture of9.9 gram (0.05 mole) of dicyclohexylphosphine, 3.5 grams (0.11 mole) ofsulfur, 25 milliliters of ammonium hydroxide, 25 milliliters of water,and 20 milliliters of methanol is heated at 60 C. in an atmosphere ofnitrogen for 1 hour. The resulting yellow solution is filtered to removeexcess sulfur and concentrated under reduced pressure. The ammonium saltof -dicyclohexyldithiophosphinic acid separates out upon 7 standing as awhite crystalline material having a melting point of 185 C.193 C.Recrystallization from benzene containing a little methanol raises themelting point to 191 C.195 C,

isobutyl ketone by refluxing the solution mixture for 1 hour underanhydrous conditions. The resulting reaction mixture is cooled to roomtemperature (21 C.-23 C.) and sodium chloride removed therefrom byfiltration. The filtrate is evaporated to dryness under reduced pres- AL EX MP E XI sure to obtain product 2,4-dm1trophenyl dlphenyldithio-Nickel salt of dlcyclvhexyldiihiophosllhillic phosphinate as a solidsoluble in benzene, acetonitrile or Example X, above, is repeated withthe exception that acetone- XA L In the solution, after removing excesssulfur, is combined E E X with a solution of 6 grams (0.025 mole) ofnickel (II) Cyclopentyl 2,4,6-triis0pr0pyl-1,3-di0xa-5- chloridehexadydrate in 25 m1llil1ters of water. The hoshacycl0Izexane-5-dithioaze e lin b s lid av'n m ltin oi t of 280 C. r Oh 1 g a 6 9 n An equimolar mixture of the sodium salt of 2,4,6-tri- 282C., 18 filtered off. Recrystallization from benzene iso m H hos hacclohexaneddithioic acid provides an analytical sample of the nickel saltof dicyclog i in i 5 H yabove) and c do m l hexyldithiophosphinic acidhaving a melting point of p p y 96 y 0 C s C bromide 111 methyl isobutylketone 15 refluxed for 3 hours EXAMPLE XII under anhydrous conditions.The resulting reaction mixture is cooled to room temperature (21 C.23C.) P dlPhenyldlfllmphOsphmale and sodium bromide removed therefrom -byfiltration. The sodium salt of diphenyldithiophosphinic acid prefiltrateis evaporated to dryness under reduced P parcd as in Example III; above,'is reacted with an equisure to obtain the product cyclopentyl2,4,6-tr1isopropylmolar amount of l-ch1oro-2,4-dinitrobenzene in methyl1,3-dioxa-5-phosphacyclohexane-5-dithioate.

TABLE I 2,4,6-triolkyl-1,3dioxa-5- +Base Temp, Ratio, Process as ExampleNo. phosphacyclohexane +S +1110 Reagent Product Salt C. AzBzC in ExampleXIV 2,4,6-tri(3-heptyl)1,3-di0xa- S 11 0 Ba(OH) 75 122:1 II Barium2,4,6-tri(3-heptyl)-l,3,dioxa 5-phosphacyclohexane. fiphosphacyclohexane-ti-dithioate. XV 2,4,6-tri(3-pentyl)1,3-di0xa- H20Ca(OH) 7O 1:2:1- II Calcium 2,4,6-tri(3-pent.yl)-l,3-dioxa-S-phospbaeyclohexane. 5-13h0sphaCyclohexane5-dithioate. XVI .12,4,6-tri(4-heptyl)1,3-dioxa- H O Mg(0H) 1:2:1 II Magnesium2,4,6-tri(4-heptyl)-l,3-

5-phosphacyclohexane. gigga-fiphosphacyclohexane-5- l 108 8. XVII2,4,6-tri(3-dodeeyl)1,3-dioxa- S 11 0 K011"-.. 60 1:221 II Potassium2,4,6-trl(3-dodecyl)1,3-

ephosphaeyclohexane. giggafip phacy lohexane-fi- 1 10a 6. XVIII2,4,6-tri(2'octyl)1,3-dioxa-5- S H O LiOH 1:2:1 II Lithium2,4,6-t1'i(2-octyl)-1,3-dioxaphosphacyclohexane.5-phosphacyclohexane-5-dithioate.

TABLE II Tcmp., Ex arrnple Reactant Salt H2O Metal Salt 0 c Q ProductSalt XIX Ammonium 2,4,6-triisopropyl-L3- H2O Zinc chloride 20Zinc2,4,6-triisopr0pyl-1,3-dioxa-5- gigga-tphosphacyclohexane-iphosphacycl0hexane-5dithioate.

1 10a 0. XX d0 1110 Copper sulfate 23 Copper2,4,6-triisopropyl-1,3-dioxa-5- phosphacyclohexane-5-dithioate. XXI do1120 Aluminum chloride hcxahydrate 25 Aluminum 2,4,6-triisopropyl-1,3-dioxa-5'phosphacyclohexane-5 dithioate. XXII d0 H2O Mercuric nitrate 21Mereuric 2,4,6-triisopropyl-1,3-

dioxa-fiphosphacyclohexane-5- dithioate.

l The reactions in this table are carried out at the ambienttemperatures indicated by inter-mingling at least one equivalent of themetal salt (B) per mole of reactant (A) in the presence of H10.Resulting product (0) is recovered by removing the water after reactiontakes place.

TABLE III Example Reactaut Reactant Process as Product Ester (A) (B) inExample (0) XXIII Sodium 2,4,6-triisopropyl-1,3-dioxa-5-phospha-3-chlorohexane XIII 3-hexy12,4,Frtriisopropyl-l,3-dioxa-5-phosphacyelohexane-5-dithioate. tcyclohexane-5-dithioate.

XXIV. Ammonium 2,4,6-tri(3 l1eptyl) 1,3-dioxa-5phosl-bromobutene-2 XIII2-butene 2,4,t'etri(3heptyl)1,3-dioxa-5-phosphapllacyclol1exane-5-dithioate.cyclohexane-5-dithioate.

XXV Ammonium 2,4,6-tri(3-pentyl)1,3-di0xa-5 phos- Allyl chloride XIIIAllyl 2,4,6-tri(3-pentyl)1,3-dioxa-5-phosphaphaeyclohexalie-fiditliioate. cyclohexane-fi-dithloate.

XXVL Sodium 2,4,6-tri(4-hepty1)1,3-di0xa-5 phospha- 2-dodecenylchloride-XIII 2-d0decenyl2,4,6-tri(4-heptyl)1,3-dioxa-5-phoscyclohexane-Erdithioate.phacyelohexane-edithioate.

XXVII Ammonium 2,4,6-tri(3-dodeeyl)1,3-dioxa-5phosp-NitrochlorobenzeneXIII p-Nitrophenyl 2,4,6-tri(3-dodecyl)1,3-di0xa-5-phacyclohexane-Mithioate. phosphacyclohexane-5-dithioate.

XXVIII Sodium 2,4,6-tri(2-octyl)1,3-dioxa-5-phospha- CyclohexylchlorideXIII Cyclohcxyl2,4,6-tri(2-octy1)1,3-dioxa-5-phoscyclohexane-5-dithioate.phaeyclohexane-5-dithi0ate.

XXIX Ammonium 2,4,fi-triisopropyl-l,3-dioxa-5'phos- Octadccylchloride.--XIII Octadecyl2,4,6-triisopropyl-1,3-dioxa-5-phosphacyelohexane-ddithioate.phacyclohexa11e-5-dithioate.

XXX Ammonium 2,4,6-tri(3-hepty1) 1,3-dioxa-5-phos- Benxylchloridc XIIIBenzyl 2,4,6-tri(3-heptyl)1,3-dioxa-5-phosphaphacyclohexane-5-dithioate.eyclohexane-5-ditliioate.

9 EXAMPLE XXXI Example V, supra, is repeated in every essential respectwith the exception that (a) dibutyl phosphine and (b) ammoniumhydroxide, respectively are-substituted with one of the following (A)secondary phosphines and (B) base reagents:

(A) SECONDARY PHOSPHINES Bis (3-e thylhexyl phosphine Bis(2,4,4-trimethylpentyl) phosphine Bis (3-chloropropy1) phosphine Bis2-butenyl phosphine Ethylhexylphosphine Diisooctylphosphine Bis3-methoxycyclohexyl phosphine 8 Bis(3-ethoxycyclopentenybphosphjne (9)Bis (2-phenoxyethyl) phosphine (10) Bis (Z-aminoethyl phosphine (1 1)Bis Z-nitropropyl) phosphine (12) Bis(Z-sulfoethyl phosphine 13) Bis(carbamylmethyl) phosphine (14) Bis( 2-ureidoethyl phosphine (15)Bis(hydroxymethyl phosphine 16) Bis( l-hydroxyhexyl phosphine (17) Bis3-carboxypropyl phosphine 18) Bis(3 -carbethoxypropyl)phosphine 19) Bis4-aminophenyl phosphine (20) Bis 2 (4-aminophenyl ethyl] phosphine (B)BASE REAGENTS Methylamine 2) Butylamine 3) Octylamine (4) 'Dodecylamine(5 Stearylamine (6) Diisopropylamine (7) Dihexylamine (8) Didodecylamine(9) Dimethylamine (10) Trirnethylamine 1 1) Tripentylamine (12)Tridecylamine 13) Tridodecylamine 14) Pyridine 15 Aniline (l6)Piperidine 17) 2-hydroxyethylamine 18) Bis( Z-hydroxyethyl) amine 19)Tris(2-hydroxyethyl) amine (20) Cyclohexylamine The corresponding (C)organic salts of disubstituted dithiophosphinic acid recovered are asfollows:

(C) ORGANIC SALTS (1) Methylammonium bis(S-ethylhexyl)dithiophosphinate(2) Butylammonium bis(2,4,4-trimethylpentyl)-dithiophosphinate (3)Octylammonium phinate (4) Dodecylammoniurnbis(Z-butenyl)dithiophosphinate bis 3-chloropr-opyl) dithiophos- (5)Stearylammonium ethylhexyldithiophosphinate (13) Tridodecylammoniumbis(carbamylmethyl)dithiophosphinate (14) Pyridiniumbis(2-ureidoethyl)dithiophosphinate 15) Anilinium'bis(hydroxymethyl)dithiophosphinate (16) Piperidiniumbis(l-hydroxyhexyl)dithiophos phinate (17) Z-hydroxyethylammoniumbis(3-carboxypropyl)- dithiophosphinate 18) Bis( Z-hydroxyethylammoniumbis 3-carbethoxypropyl)dithiophosphinate (19) Tris(2-hydroxyethyl)ammonium bis (4-aminophenyl)dithiophosphinate (20) Cyclohexylammoniumbis[2(4-aminophenyl)- ethyl] dithiophosphinate The following exampleswill serve to illustrate the utilities of typical compounds of theinvention.

EXAMPLE XXXII Herbicidal activity is exemplified by initially dissolvingtest compound: 2,4,6-triisopropyl 1,3dioxa-S-phosphacyclohexane-S-dithioic acid in /50 acetone/water mixturein sufiicient quantity to provide the equivalent of 3 pounds per acre.The solution is sprayed on radish,

- tomato and pea plants at a pressure of 30 p.s.i. and, after EXAMPLEX)O(III This example illustrates the effectiveness of nickel and Zincsalts of 2,4,6-triisopropyl-1,3-dioxa-5-phosphacyclohexane-S-dithioicacid as illustrative water-insoluble compounds for anti-wear orextreme-pressure lubricants.

The basic fluids for demonstrating this effect are Fractol A (a mineraloil) and DOS (i.e., di(2-ethy1hexy1)sebacate), a typical diester typesynthetic lubricant. Solutions containing the test additive in each ofthe base fluids are tested using the 4-Ball wear tester. The latterconsists of four 1":0001" high carbon chrome alloy steel balls (grade1000) arranged in the form of an equilateral tetrahedron. The threelower balls are held immovable in a cup and they form a cradle in whichthe upper ball is placed. The upper ball is held in a drill chuck whichis caused to rotate about a vertical axis under specific conditions ofload and speed. The cup containing the three lower balls is filled withthe lubricant to be tested such that the balls are completely covered.During the test circular or near-circular scars are worn on the surfaceof the three stationary balls. The average diameter of the scars is ameasure of wear which depends on the load, speed, time of test andspecific lubricant present. By holding all other variables constant, the

lubrication properties of various fluids can be tested.

Lubricity tests are performed in the above-described 4-ball wear machineby testing both the nickel and zinc salts of the dithioic acids asindicated in the Table IV below as NiA and Z11A respectively. With aload of 28.7 kilograms, a speed of 390 rpm. and a time of sixty minutes,the results are set forth in the table.

TABLE IV.LUB RIOIIY TEST DATA It will be seen from the summarized datathat the coefficient of friction of DOS+0.25% NiA or 0.3% ZnA asdetermined by measuring the torque on the cup is approximately one-halfthat of the untreated DOS.

During the testing, a reduction of frictional squeal to almost zero isnoted when either NiA or ZnA is added to the base fluid. It isunderstood that by definition NiA is the nickel salt of2,4,6-triisopropyl-1,3-dioxa-5-phosphacyclohexane-S-dithioic acid andZnA is the zinc salt of 2,4,6-triisopropyl 1,3dioxa-S-phosphacyclohexane-S-dithioic acid.

I claim:

1. An organophosphorus compound corresponding to the formula wherein Yrepresents a member selected from the groupconsisting of hydrogen;ammonium; alkali metal; alkaline earth metal; copper; mercury; zinc;nickel; aluminum; alkyl; alkenyl; cyclopentyl; cyclohexyl; benzyl;nitrophenyl; and R and R each represents alkyl having from 1 to 10carbon atoms.

2. 2,4,6 triisopropyl 1,3 dioxa 5 phosphacyclohexane-S-dithioic acid.

3. The ammonium salt of 2,4,6-triisopropyl-l,3-dioxa-5-phosphacyclohexane-S-dithioic acid.

4. The sodium salt of 2,4,6-triisopropyl 1,3 dioxa-S-phosphacyclohexane-S-dithioic acid.

5. The nickel salt of 2,4,6-triisopropyl-1,3-dioxa-5-phosphacyclohexane-S-dithioic acid.

6. The zinc salt of2,4,6-triisopropyl-1,3-dioxa-5-phosphacyclohexane-S-dithioic acid.

No references cited.

TOBIAS E. LEVOW, Primary Examiner.

H. M. S. SNEED, Assistant Examiner.

1. AN OORGANOPHOSPHORUS COMPOUND CORRESPONDING TO THE FORMULA
 6. THEZINC SALT OF 2,4,6-TRISOPROPYL-1,2-DIOXA-5-PHOSPHACYCLOHEXANE-5-DITHIOICACID.